Adults randomized to personalized meal schedules—derived from two weeks of app-based dietary records—lost 2.10 kg more than controls over six weeks (95% CI: −2.86 to −1.34; P<0.0001), with a corresponding BMI reduction of 0.70 kg/m². Crucially, neither self-reported caloric intake nor macronutrient composition differed between groups, suggesting the weight loss stemmed from meal timing regularization itself rather than eating less. Sleep quality also improved meaningfully (Pittsburgh Sleep Quality Index: −1.47 points; P=0.0006), and greater reductions in meal-timing variability correlated dose-dependently with greater weight loss.
These findings land in a rapidly maturing field of chrono-nutrition, where disrupted circadian feeding patterns have been linked to impaired insulin sensitivity, elevated cortisol rhythms, and dysregulated appetite hormones—mechanisms that could explain weight loss independent of caloric reduction. A 2.1 kg effect over just six weeks without prescribed restriction is clinically notable, rivaling short-term low-calorie interventions. However, several cautions apply: this is a single-center pilot with 100 completers, relying on self-reported dietary data (prone to under-reporting bias), and the control arm's 18-hour eating window is itself a modest intervention, potentially underestimating true effect sizes. Objective metabolic markers—insulin, ghrelin, cortisol—were not measured. Critically, as an unreviewed preprint posted to medRxiv, these results have not undergone peer scrutiny and should be treated as preliminary. If confirmed in larger trials with objective circadian measures, personalized meal timing could become a low-burden, scalable metabolic health tool.
